[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Nursing](https://durgical.com/en/nursing/) › [Medical–surgical nursing](https://durgical.com/en/nursing/areas/med-surg/) › Dengue, malaria and other tropical fevers on the ward: warning signs, fluid monitoring and vector protection

# Dengue, malaria and other tropical fevers on the ward: warning signs, fluid monitoring and vector protection

- Assessment

The nurse counts the days of fever, looks for warning signs at every check, monitors fluids closely and keeps mosquitoes away from the patient.

Updated Nov 13, 2026

## Key points

- The dengue critical phase starts as the fever falls and usually lasts 24–48 hours: the patient may look better just as the risk rises.
- Dengue warning signs: abdominal pain or tenderness, persistent vomiting, fluid accumulation, mucosal bleeding, lethargy or restlessness, a large liver and a rising haematocrit.
- A patient with warning signs is admitted and monitored closely: vital signs, intake, urine output and haematocrit.
- For dengue fever, aspirin and NSAIDs are avoided; the antipyretic is the one the doctor orders.
- Every suspected malaria case is confirmed with a parasite test (microscopy or rapid test).
- A febrile patient sleeps under a bed net so that mosquitoes do not carry the virus or parasite to others.

## What it is

Dengue and malaria are spread by mosquitoes and are common in Colombia. In dengue there is no specific antiviral drug: care is supportive, and the danger comes in the critical phase, which starts as the fever falls, when leaking plasma can cause shock within hours, sometimes in a patient who still looks well. Recognising the warning signs and starting fluid care early saves lives. In malaria, every suspected case is confirmed with a parasite test, because early symptoms look like many other fevers and falciparum malaria can become severe within a day. The nurse also protects other people: a febrile patient sleeps under a bed net. Chikungunya, Zika, leptospirosis and yellow fever have their own condition pages.

## Reference values

- Dengue fever usually lasts 2–7 days; the critical phase usually falls about 3–8 days after the fever began.
- Severe dengue: shock from plasma leakage, fluid accumulation with breathing distress, severe bleeding, or severe organ impairment.
- Monitoring with warning signs: vital signs, intake, urine output and haematocrit every 4–6 hours, or more often as ordered.
- Monitoring in severe dengue: vital signs continuously or at least every 1–2 hours in the critical phase, with pulse pressure, capillary refill and mental status.
- Severe malaria warning signs: extreme tiredness, impaired consciousness, repeated convulsions, difficulty breathing, dark or bloody urine, jaundice and abnormal bleeding.

## How to measure it (and why)

- Ask on which day the fever began and record the illness day at each shift: the dengue critical phase starts as the fever falls.
- Look for every warning sign at each assessment and record them: patients with warning signs progress more often to severe dengue.
- Measure vital signs, intake, urine output and haematocrit as often as ordered: plasma leakage shows first in these values.
- Check pulse pressure, capillary refill, skin temperature and mental status: early shock can hide in a patient who looks well.
- Encourage oral fluids, preferably oral rehydration salts, if allowed, and run IV fluids exactly as ordered: fluid care is the treatment.
- Treat fever only with the antipyretic ordered and tepid sponging; no aspirin or NSAIDs: they raise the risk of bleeding.
- When malaria is suspected, make sure the parasite test is taken promptly: early symptoms are nonspecific and severe malaria progresses fast.
- Keep the febrile patient under a bed net and use repellent as the institution allows: a mosquito biting the patient can infect others.
- Before discharge, teach the warning signs and to come back at once if any appear: the critical phase can begin at home.

## How to read it

- A rising haematocrit is itself a warning sign: it points to plasma leakage.
- In the recovery phase, leaked fluid is reabsorbed, urine output increases and the platelet count recovers; the rash may peel and itch.
- Antibiotics do not treat dengue, which is caused by a virus.
- Malaria does not pass from person to person, except through blood transfusion or contaminated needles.
- Infants, children under 5, pregnant women, travellers and people with HIV are at higher risk of severe malaria.

## Next step: when to call for help

- Any new dengue warning sign: tell the nurse in charge and the doctor at once.
- Cold skin, slow capillary refill, a narrowing pulse pressure, restlessness or drowsiness: possible shock, call for urgent help.
- Bleeding from the gums or nose, or blood in vomit, stools or urine: report at once.
- In malaria, confusion, convulsions, difficulty breathing, dark urine or jaundice: an emergency.
- A urine output below the target set in the care plan, or a patient who cannot drink: inform the doctor.

## Test yourself

Think of the answer, then tap the question to see it.

## When does the critical phase of dengue begin, and why is it easy to miss?

It begins as the fever falls and usually lasts 24–48 hours. The patient may look better, yet plasma leakage can cause shock within hours.

## Which four warning signs of dengue can you name?

Any four of: abdominal pain or tenderness, persistent vomiting, fluid accumulation, mucosal bleeding, lethargy or restlessness, a large liver, a rising haematocrit.

## Why are aspirin and NSAIDs avoided in dengue?

They increase the risk of bleeding. The fever is treated with the antipyretic the doctor orders and tepid sponging.

## Why does a febrile patient with dengue or malaria sleep under a bed net?

A mosquito that bites the patient can pick up the virus or parasite and infect other people.

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## Elsewhere in DurgiPedia

- [Shock: the clinical signs and the types](https://durgical.com/en/clinical-exam/shock-the-clinical-signs-and-the-types/)

## Connections

## Related 3

- [Fluid balance: recording intake and output](https://durgical.com/en/nursing/fluid-balance-recording-intake-and-output/)
- [Early warning scores (NEWS2) and when to escalate](https://durgical.com/en/nursing/early-warning-scores-and-when-to-escalate/)
- [Sepsis and septic shock: screening, the first-hour bundle from the nursing side and watching organ dysfunction](https://durgical.com/en/nursing/sepsis-and-septic-shock-screening-the-first-hour-bundle-from-the-nursing-side-an/)

## Related conditions 6

- [Dengue](https://durgical.com/en/conditions/dengue/)
- [Malaria](https://durgical.com/en/conditions/malaria/)
- [Chikungunya](https://durgical.com/en/conditions/chikungunya/)
- [Zika virus infection](https://durgical.com/en/conditions/zika-virus-infection/)
- [Leptospirosis](https://durgical.com/en/conditions/leptospirosis/)
- [Yellow fever](https://durgical.com/en/conditions/yellow-fever/)

[← All of nursing](https://durgical.com/en/nursing/)

Educational content for students; it does not replace your institution's protocols, supervised clinical training or a prescriber's order. Dose-calculation examples use made-up numbers: they are educational, not a clinical order.

Sources: [Clinical signs and symptoms of dengue](https://www.cdc.gov/dengue/hcp/clinical-signs/index.html) (Centers for Disease Control and Prevention (CDC), 2025); [Clinical care of dengue](https://www.cdc.gov/dengue/hcp/clinical-care/index.html) (Centers for Disease Control and Prevention (CDC), 2025); [Dengue](https://www.paho.org/en/topics/dengue) (Pan American Health Organization (PAHO), 2025); [Malaria, fact sheet](https://www.who.int/news-room/fact-sheets/detail/malaria) (World Health Organization (WHO), 2025).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/nursing/dengue-malaria-and-other-tropical-fevers-on-the-ward-warning-signs-fluid-monitor/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/nursing/dengue-malaria-and-other-tropical-fevers-on-the-ward-warning-signs-fluid-monitor/